Wednesday, February 27, 2013

It is common for beginner microscope users to incorrectly adjust the condenser on their microscope. The condenser is located beneath the stage on a biological microscope or a polarizing microscope and controls the amount of light that passes from the illuminator, up through the stage and the specimen. The microscope condenser regulates the intensity of the light by closing or opening the condenser diaphragm or by adjusting the height of the condenser.

Microscope condenser from a polarizing microscope.

When using the microscope the light should not be adjusted using the condenser (this is a common mistake). Use the intensity control on the light to adjust brightness of the lamp. If you try to adjust the light coming through the microscope by closing the condenser diaphragm it diminishes the resolution of the microscope. Always open the diaphragm on the microscope condenser as wide as possible while still achieving a good image. To achieve sufficient contrast it should be closed just slightly - a good rule is to have the condenser open to at least 2/3 maximum capacity. Better results are almost always achieved by placing the condenser in the highest position.

Once you view the insects under a dissecting microscope, you may wish to view more details of a specific part of the insect. If this is the case, you will need to dissect the insect and prepare a slide. This will allow you to view a flat specimen under a biological microscope, which has more magnification. You also need to prepare a slide because when using a biological microscope the specimen must be translucent (allow light to pass through it). A stereo dissecting microscope has light above and beneath the stage, whereas a biological microscope only has light that shines up from beneath the stage.

If you are just starting to view insects with the microscope and only have access to one type of microscope, it is recommended to start with a basic dissecting stereo microscope, as these are easier to view the entire insect at once and do not require slide preparation.

Thursday, February 21, 2013

Discovering a variety of microscopic specimens in pond water is a common biology experiment for students both young and old. Below are some tips that will help you collect and identify microscopic pond life under your biological microscope.

The easiest way to collect small pond life and organisms is to squeeze water from plants or pond scum into a container. Scraping growth from water plants or anything covered in green or brown growth will usually result in a high content of microscopic pond life.

A plankton net is best for free swimming planktonic species. A plankton net is a very fine mesh cloth with a small container at the end. The plankton net can be used to concentrate the material squeezed out of water plants as well.

Hydra can be collected by putting duckweed or other waterweed into a glass jar full of water. Wait for several hours and the hydra can be found attached to the glass.

Keep your pond organisms in a shallow container. A large surface with only a copule of cm of water ensures there is enough oxygen in the water. If you wish to culture algae, cook some garden soil in water. After cooling, you can incubate it with the algae you want to grow.

Desmids are beautiful small algae most abundant in waters without too many nutrients or acid waters. Bogs are good collecting spots for desmids.

Amoeba are protozoa that often feed on material on the bottom sediment of a pond. The best method for collecting amoeba is to lower a jar upside down until it is positioned just above the mud surface. Slowly let the air escape so the top layer is sucked into the jar.

When viewing brown growth scraped off surfaces, there is a good chance you will find diatoms.

The best way to view your microscopic pond life is by placing the sample on a depression slide with a glass cover slip. Put your specimen under the microscope and start with the lowest magnification. Once you bring the sample into focus, increase the magnfication. If you are having trouble identifying your specimen, send us an email with the image attached. We will be happy to try and help you determine which microscope pond life you have come across!

Tuesday, February 19, 2013

Feathers have many functions including insulation from wet and cold. Birds often pluck feathers to line their nest or insulate eggs or their young. Feathers are used to control flight and sometimes feathers help camouflage against predators.

This is the feather that was used to capture the microscope images below. It fits in the palm of your hand.

Friday, February 15, 2013

Finding fun things to view with your stereo microscope is easier than you might think. If you simply walk around your house or outside in the back yard you can find an endless supply of interesting samples for microscope viewing.

Here are a few images captured under the MW5-L5 stereo zoom microscope (10x - 40x magnification). This stereo dissecting microscope is used frequently in schools and sometimes for manufacturing inspection.

Printed holiday napkin.

Penny.

Flower.

Toffee-covered almond.

Wax shavings.

Rosewood.

Have any ideas of things you would like to view under the microscope? Or have some of your own microscope images you would like to share with us? Visit our Facebook page and share your images and ideas with us!

Wednesday, February 13, 2013

Moina thrives in ponds and reservoirs, but primarily inhabits temporary ponds or ditches. Moina is a genus that has the ability to survive in waters containing high salinity and other impurities, including salt pans.

Moina are primarily found in ponds or ditches. The males are smaller than females and the period to reach reproductive maturity takes four to five days at 26 degrees Celsius.

Moina and Copepod image courtesy of Dave Wilson.

The image above was captured with a biological microscope. The Moina and Copepod were captured in Australia by one of Microscope World's customers.

Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic (drifting in sea waters) and some are benthic (living on the ocean floor), while some may live in wet terrestrial places such as swamps, under leaf fall in wet forests, bogs, springs, ponds, damp moss or water-filled recesses of plants. Copepods are sometimes used as bioindicators.

Monday, February 11, 2013

Stereo microscopes offer low magnification and are perfect instruments for viewing zebrafish in the classroom. Stereo microscopes are sometimes referred to as dissection microscopes because they have a large amount of room to work under the microscope while looking through the eyepieces.

Viewing zebrafish under a dissecting microscope is a simple process. Start by setting your stereo microscope on a flat table with plenty of working room. When viewing stained zebrafish embryos, you will want to use the top (reflected) light source and place your specimen on a solid white stage plate.

Your zebrafish will most likely be in a petri dish. Center the dish under the microscope light and adjust the eyepieces so you will be able to look through the microscope comfortably. Start with the magnification at the lowest setting and bring the zebrafish into focus, then slowly increase the magnification. If you are unable to locate the zebrafish, move the petri dish slightly so a different part of the specimen comes into view - it can sometimes be tricky to initially get the zebrafish into the field of view.

When viewing the zebrafish with a stereo microscope you will see a three-dimensional round zebrafish. Because the zebrafish is not a flat object, there may be times that not all parts of the zebrafish are in focus at the same time. In order to view the other parts of the zebrafish in focus you may need to adjust the focusing knob slightly.

When finished viewing your zebrafish with the stereo microscope, turn off the light, return the zebrafish specimen to its proper location and place the dust cover back over the microscope to keep particles and dust from settling on the optics.

Thursday, February 7, 2013

Polarizing microscopes are used for specialized medical and industrial applications, such as identifying crystals or fibers suspended in liquid, identifying minerals in core samples and detecting defects in semiconductors.

Polarizing microscopes are used for toxicology, chemistry, pharmaceutics, medicine, the pulp/paper industry, and forensic medicine. They can also be utilized in finding stress points in metal, glass and other materials.

Vitamin C captured at 400x magnification under a polarizing microscope.

Sugar captured at 100x magnification under the polarizing microscope.

Because polarizing microscopes use a polarizer and an analyer to affect the light passing through the microscope, often the images produced are brilliant in color.

Microscope World most recently had a safety pin handy, so this was thrown under the HSZ6-TBL stereo microscope in order to check out the microscope's clarity and reflection characteristics. (Often metal objects will reflect light differently under the microscope depending on the type of light being used).